implement window surface

[Brian Paul]

Jon Smirl wrote:
> Don't I need to implement window surfaces in the fbdev EGL driver? In
> other words the ability to create a surface that will draw to a
> clipped rectangle on an existing screen surface.  Without clipped
> surfaces how can you implement a non-composed Xserver?

The eglCreateWindowSurface() function is designed to be used in 
conjunction with the native window system's windows (X window or Win32 
window, etc).  It takes a <NativeWindowType> parameter.  So you'd use 
the native window system API to manage the window (XMoveWindow, 
XResizeWindow, XMapWindow, etc).

So in our X-less EGL environment we'd probably need to add all those 
sorts of functions.

Another option I've been considering is to develop a new OpenGL/Mesa 
extension that extends the glScissor feature to allow clipping against 
a list of rectangles, not just one.  This would be used to implement 
cliprects for window regions.  The DRI drivers already support this 
internally for window clipping so it shouldn't be too hard to implement.

What do the XGL people think of that?

-Brian